The primary objective of this study is to determine the New Ballard Maturation Score (NBS) in sufficient numbers of low birth weight infants with good documentation of maternal dates to calculate 95% Confidence Interval for infants less than 30 weeks gestation. Secondary objectives are to compare the NBS with the best obstetrical estimate of gestational age in terms of prediction of death or severe morbidity, duration of hospital stay, and predictor of illness score.